An Efficient Self-Assembly of CdS Nanowires–Reduced Graphene Oxide Nanocomposites for Selective Reduction of Nitro Organics under Visible Light Irradiation

The CdS nanowires–reduced graphene oxide nanocomposites (CdS NWs–RGO NCs) combining one-dimensional (1-D) with two-dimensional (2-D) structures are successfully synthesized by a simple and efficient electrostatic self-assembly method, followed by a hydrothermal reduction process. The probe reactions for photocatalytic selective reduction of aromatic nitro organics in water under visible light irradiation are utilized to evaluate the photoactivity of the as-prepared CdS NWs–RGO NCs. The CdS NWs–RGO NCs exhibit significantly enhanced photoactivity as compared with the CdS nanowires (CdS NWs). The addition of RGO into the matrix of CdS NWs in a controlled manner is able to efficiently enhance the lifetime and transfer of photogenerated charge carriers from CdS NWs under visible light irradiation. Furthermore, the presence of RGO also improves the adsorption capacity of CdS NWs–RGO NCs toward aromatic nitro organics. These two primary factors result in the drastic photoactivity improvement of CdS NWs–RGO NCs toward selective reduction of nitro organics to the corresponding amino organics in water under visible light irradiation. In addition, the possible photocatalytic reaction mechanism is proposed. It is hoped that our work could not only offer useful information on the fabrication of various specific 1-D semiconductor–2-D RGO nanocomposites but also open a new window of such 1-D semiconductor–2-D RGO nanocomposites as visible light photocatalyst in the promising field of selective organic transformations.